Johannes from Clearlight Saunas is making a straightforward argument: buying an infrared sauna without understanding the technology is a mistake you'll live with for years. Warranty terms, heater type, infrared spectrum — these aren't marketing details. They're the difference between a sauna that genuinely changes your biology and one that's a warm wooden box.
He's right. And as someone who's been deep in this research, I want to add something the manufacturer's video naturally won't tell you.
Most of the compelling sauna research — the Finnish studies showing a 63 percent reduction in sudden cardiac death, the Alzheimer's risk data, the all-cause mortality numbers that Rhonda Patrick has done so much to popularize — was done on traditional Finnish dry heat saunas. Not infrared. Not carbon heaters. Not full-spectrum LED panels. Old-fashioned rocks and steam, at temperatures between 174 and 200 degrees Fahrenheit.
That doesn't mean infrared saunas don't work. It means the evidence base is thinner, and consumers deserve to know that. The physiological mechanisms — heat shock protein activation, cardiovascular adaptation, core temperature elevation — are real regardless of heat source. But if you're buying an infrared sauna because you read about the Finnish longevity studies, understand that you're extrapolating.
On the heater question, Johannes is on solid ground. The near-infrared versus far-infrared distinction matters because these wavelengths penetrate tissue differently. Near-infrared (around 800 to 860 nanometers) doesn't penetrate deeply — it primarily stimulates the skin and surface tissue, which is why it's useful for red light therapy and wound healing. Far-infrared penetrates more deeply and is better at raising core temperature. A full-spectrum heater combines both, which gives you more flexibility but also more complexity to evaluate.
The point about LEDs is particularly important and often missed: LEDs are excellent for targeted red light therapy, but they don't generate enough thermal energy to meaningfully elevate core body temperature. If core temperature elevation is your goal — and it should be, because that's what activates heat shock proteins and the cardiovascular adaptations — you need actual infrared heaters, not LED panels marketed as "infrared."
If you're buying an infrared sauna, ask one question before anything else: what is the target core temperature elevation, and how does the heater achieve it? A true lifetime warranty signals confidence from the manufacturer, but the technology underneath it matters more than the paperwork around it. Carbon heaters with a full spectrum output, aimed at consistent core temperature elevation of one to two degrees Celsius per session, is the protocol that tracks closest to the existing research.
There's a quiet irony here. The wellness industry has largely shifted toward infrared because it operates at lower ambient temperatures — more comfortable, more accessible, easier to install in a home. But the discomfort of traditional Finnish sauna is part of the mechanism. The dynorphin response, the heat shock protein cascade, the cardiovascular strain that forces adaptation — these are stress responses. Comfort and adaptation are, in some ways, opposites. The best sauna for you is the one you'll actually use consistently. But don't mistake comfort for equivalence.